Orchard heater



July 17, 1934. 5 w. NIGG 1,966,642

ORCHARD HEATER Filed March 25, 1932 2 Sheets-Sheet l July 17, 1934. G, w NIGG 1,966,642

ORCHARD HEATER Filed March 25 1932 2 Sheets-Sheet 2 nu J1? 1 f 1 ununnuuunu Inventor 014/ 4," Attorneys Patented July 17, 1934 '1 STATES UNIT AT? OFFIQE ORCHARD HEATER tion of California Application March 25, 1932, Serial No. 601,175

9 Claims.

This invention relates to fuel burning devices and particularly to orchard heaters for protecting trees or other plants from frost.

A broad object of the invention is to provide a heater that will burn at a uniform rate for a long period of time without reloading.

Another object is to provide a heater in which the rate of burning of the fuel can be accurately regulated between wide limits, and in which the fire can be readily extinguished at will.

Another object is to provide a magazine heater for burning solid fuel efiiciently at a uniform rate.

Still another object is to provide a heater that can be manufactured inexpensively; that can be maintained in use at low cost, and is not subject to rapid depreciation.

At present there are two general types of orchard heaters in use, namely, those using oil and those using solid fuel. Oil heaters have probably been used more widely, particularly in regions Where oil is produced, than those burning solid fuel, but oil heaters are open to the objection that they produce a great deal of soot and smoke and that they must be refilled after each burning even though all the oil has not been consumed. It has been necessary to refill them because of the fact that the volatile constituents of the oil are consumed first, thus leaving a heavy residue that is difficult to ignite.

Solid fuel heaters as manufactured in the past have been open to the objection that they were difficult to ignite, and the entire body of fuel became ignited at once, thus producing an intense heat for a short time which thereafter rapidly diminished as the fuel was consumed. Furthermore, due to the fact that the entire body of fuel ignited at once, it was difiicult to extinguish the fire before the fuel was all consumed, and this not only wasted fuel but necessitated refilling the heaters after each firing.

In accordance with the present invention, a heater is provided that burns petroleum coke, a fuel that can be obtained cheaply and that produces practically no soot or smoke. Furthermore, the construction of the heater is such as to provide a fuel magazine of relatively large capacity, with a small burning zone at the bottom in which the fuel burns uniformly, the fuel being automatically supplied to the burning zone from the magazine as it is consumed.

The construction of the heater is such as to rovide a cross draft from the center of the burning fuel body to the exterior of the heater through apertures provided in the outer wall of the heater, and the rate of the burning may be regulated between wide limits by covering more or less of the draft holes in the outer wall by a sliding sleeve.

A full understanding of the construction and operation of my heater can best be had from the following detailed description read in connection with the drawings in which,

Figure l is an elevational View partly in section of a complete heater.

Figure 2 is a horizontal sectional view in the plane IIII of Figure 1.

Figure 3 is a sectional detail view in the plane IIIIII of Figure 1 showing the sleeve locking mechanism.

Figure 4. is a detail elevational view of a heater having a modified form of grate;

Figure 5 is a horizontal sectional View in the plane VV of Figure 4;

Figure 6 is an elevational sectional view of still another form of grate construction; and

Figure 7 is a horizontal sectional view in the plane VIIVII of Figure 6.

Referring to Figure 1, my heater comprises a cylindrical container 1 supported by a base designated generally at 5, which in turn is supported a short distance above the ground by legs 6. Base 5 is preferably formed of cast iron and is of circular shape as shown in Figure 2. It has a bottom 9, an outerwall '7, and an inner wall 8, which form a liquid-tight receptacle adapted to contain fuel oil for igniting purposes. Apertures 10 are provided in the bottom 9 of the base to admit air, these apertures having walls extending up even with the tops of the outer wall '7, and the inner wall 8 to prevent the liquid fuel from flowing out therethrough.

The cylindrical container 1 is preferably constructed of heavy sheet iron or steel and has an internal diameter only slightly greater than the external diameter of the outer wall '7 of the base 5, so that the end of the container fits down over the walls 7. To prevent the container 1 from sliding down over the base 5, the wall of the container is indented at 20 to engage the top of the wall '7.

Centrally positioned upon the container base 5 is a conical grate 11 which extends up within the cylindrical container 1 and is provided with draft apertures 12 in its walls.

The grate 11 is retained in its proper position on the base 5 by lugs 13 formed integrally with the base 5 and extending about the circumference of the grate 11.

The upper end of container 1 is closed by a cover 3, which is provided with a downwardly extending flange which fits tightly over the rolled upper edge 4 of the container. By this construction the cover 3 can be readily removed but forms a substantially air-tight closure for the container when it is in position.

The lower portion of the cylindrical container 1 is provided with numerous draft outlet holes 2, and to variably cover and seal these apertures, an expansible draft sleeve 14 is provided. This draft sleeve 14 is constructed of flexible sheet metal of len th slightly greater than the circumference of the cylindrical container 1 so that when wrapped about the container the edges overlap as shown in the drawings. To permit a tight seal, one vertical edge of the draft sleeve 14 is left smooth so that it lies flat between the other end of the sleeve and the container 1. The other vertical edge of the draft sleeve is provided with a rolled edge 15. The construction described is clearly disclosed in Figure 3.

A clamping means is provided to secure the expansible draft sleeve 14 tightly about the container 1, this means comprising a locking lever 16, the ends of which are pivotally secured to the draft sleeve adjacent its rolled edge by hinges 19, and two links 17, each of which is pivotally secured at one end to the locking lever 15 and at the other end to the draft sleeve 1s adjacent its opposite edge, by hinges 18. By pulling the handle 16 away from the draft sleeve '14, the sleeve may be expanded sufliciently to permit it to be freely slid up or down over the container 1, whereas when the handle 16 is moved into locking position adjacent the sleeve 14 as shown in Figure 3, the sleeve is locked tightly about the container 1.

desired position, and clamping it in place by moving the locking lever against the side of the container. The oil in the base 5 is then ignited and it in turn ignites the coke in the bottom of the container 1. If desired, the oil receptacle may also be filled after the solid fuel has been placed in the container 1, by inserting the spout of a filling can through one of the apertures 2 near the base of the container.

It will be observed that since the top of container 1 is sealed by cover 3, and since the upper half of container 1 is not provided with any draft apertures, as is the lower half, that the only openings in the container are openings 12 in grate 11, the openings 10 in the base 5, and the apertures 2 in the lower half of container 1. Hence all air for supporting combustion must be supplied through these openings and they must likewise suffice for the removal of all the products of combustion. .As a result, a cross draft is created, fresh air for supporting combustion flowing in through the openings 10 in the base 5 and through the openings 12 in the conical grate 11, thence through the burning mass of fuel and out through the apertures 2.

' The air supplied in this manner is sufiicient to support very vigorous combustion in the lower part of the container which heats the wall of the container 1 until they glow and thus radiate a great deal of heat. This intense heating of the walls of the container is desirable for the reason that a relatively large portion of the heat developed is given ofi as radiant heat rather than as heated gases. Radiant heat is more useful in that it is absorbed by the adjacent trees or other vegetation, whereas hot gases tend to rise quickly and much of the heat is carried well above the trees and produces no useful effect. Furthermore, due to the fact that the perforations 2 form a relatively large proportion of the area of the lower part of the container 1, much of the heat from the glowing fuel within the container is radiated directly through these apertures 2 without having to pass through the metal wall of the container.

If maximum heat is to be obtained, the slidable damper sleeve M will be placed in its uppermost position as shown in Figure 1, in which all of the apertures 2 are exposed, thus permitting combustion of the whole mass of fuel within the perforated area of the container. If less heat is required, the damper sleeve 1 is moved down to cover a portion of the perforated area of the container, and the rate of burning can regulated to a nicety by this means, since no circulation of air through the fuel can take place above the bottom of the damper sleeve 14. When heat is no longer needed, the damper sleeve 14 can be moved clear to the bottom of container 1, thus closing all the apertures 2 and preventing any draft through the fuel. The fire then quickly dies out.

In any form of orchard heater it is impossible to maintain galvanizing or other protective coating on the portions of the device that become highly heated, and, as a result, such portions quickly rusted if exposed to the elements. In the heater described, the only portion that becomes highly heated is the lower half of the container 1, the base 5 and the grate 11. The remaining parts will therefore retain a coat of zinc to protect them from rust, and when the heater'is not in use the lower portion of container 1 which would normally be exposed to the elements and would therefore be subject to rust may be protected by clamping the draft sleeve 14 about this lower portion, thus enclosing it and preventing it from being wet during storms. By clamping the sleeve 14 about the lower portion of the container the apertures 2 are also sealed thus preventing fuel within the container from being Wet during rains. Because of this feature, it is feasible to leave the heater filled with fuel in the orchard throughout the year so that it is ready for use at all times.

Although magazine heaters for burning solid fuel have been used before, those of which I am aware depend upon the feeding of fuel from a magazine through a restricted opening to the burning chamber and are therefore subject to clogging unless uniformly fine fuel is used. In my construction, the magazine portion of the heater is of the same outside diameter as the burning portion and this permits the use of fuel in irregularly shaped and sized lumps with- .out any possibility of clogging.

As shown in Figure 1, the oil reservoir formed by base 5 extends into the space below the conical grate 11 as well as below the fuel in the container 1 outside of the grate. This is advantageous in that the flame from the burning oil within the grate 11 rises up through the grate and passes through the apertures 12 into the solid fuel to ignite it simultaneously over the entire surface of the grate. As a result of this construction, the entire body of fuel is quickly ignited so that there is little delay in obtaining the maximum output of heat.

Referring to Figures 4 and 5, an alternative form of base is used in which the reservoir for igniting oil is restricted to the space surroundthe inner wall 8a and within the base of the grate 11a. By this construction ignition of the solid fuel takes place solely from the oil flame which ascends into the conical grate 11a and out through the apertures 12a into the solid fuel. To faciltate refilling of the oil reservoir without dismantling the burner, an oil filler tube 21 is provided which extends outwardly from the reservoir defined by the bottom 9a, inner wall 8a and the outer wall 22, to the wall of the container la. An aperture 23 is provided in the wall of the container 1a juxtaposed to the outer end of the tube 21 for the insertion of the spout of a filling can. The tube 21 is inclined upwardly as shown so that oil from the rservoir will not how out therethrough.

The form of construction described in connection with Figures 4 and 5 is also advantageous that it permits the portion of the bottom 9a of the base outside of the grate 11a to be perforated with a large number of apertures as shown at 18c. This facilitates the removal of the ash from the burned fuel and reduces the possibility of the lower portion of the container becoming clogged with ash.

In some localities it may be desirable to use solid fuel, such as resinous or paraihne treated coke, peach pits or various forms of treated sawdust or chips, for igniting fuel instead of oil. Where such kindling is to be used, the base construction shown in Figures 6 and 'I may be employed. Referring to these figures, the bottom of the base 91) is provided with apertures 101) as described above in connection with Figures 4 and 5 but no oil reservoir is provided, a solid kindling being contained in a basket 24 which is supported below the bottom 91) of the base by a pair of shelves 25 formed integrally with the legs 6b. The basket 24 is provided with outwardly extending flanges 26 which rest upon the supporting shelves 25 so that the basket can be readily slid in or out of position to fill it and to light the kindling. The flame from the kindling ignites the solid fuel in the heater by passing through the apertures 10b and also through the apertures 12?) in the conical grate 11 3.

Although a heater has been disclosed in which the height of the magazine chamber is approximately equal to that of the burning chamber, 1 am not restricted to any particular dimensions in respect. In other words, the heig t of the cy--ndrical container 1 may be made as great as desired to increase the fuel capacity and the time of continuous burning. The actual dimensions of course will be determined by the conditions of use and the cost of manufacture.

As previously pointed out, the construction of the damper sleeve 14 whereby it can be expanded to move it into a desired position and thereafter be clamped tightly about the com tainer 1 desirable in that it permits the damp or to be tightly sealed about the container 1 and thus completely prevent combustion of fuel within the portion covered. This construction is further advantageous for the reason that small pieces of solid fuel may project through the apertures 2 which would interfere with the lower'ng of the sleeve 14 if the latter were solid and dimensioned to fit snugly about the con tainer at all times. The expansible sleeve is sufiiciently large when in expanded position to pass freely over any pieces of fuel projecting through the apertures 2 and when the sleeve is subsequently clamped tightly about the container l forces any such pieces of fuel back into the container.

A heater of the approximate dimensions shown in the drawin s can generally be used for at least two, and possibly three, periods of heating without replenishing the fuel supply. This greatly reduces the cost of mainte nance over that of oil heaters in which the fuel must be replenished after each burning period. Spare fuel may be stored in the grove or orchard in sacks or other conta ners and may be added to the heaters by removing the lids 3 either during combustion or when extingnished without in any way affecting the lighting or burning properties of the heater.

I claim:

1. An orchard heater for burning solid fuel, compris'ng a vertical tubular fuel container, and a base comprising a hollow grate extending up into said container, the lower end of said hollow grate being of less diameter than the diameter of said base, and an oil receptacle extending both within and without the lower end of said hollow grate.

2. An orchard heater comprising a vertical tubular member having perforations in its lower portion only, means for forming an airtight closure on the upper end of said member, and a base for supporting said member including a hollow grate centrally positioned within said member and extendng upwardly therewithin, the only opening to the interior of said hollow grate from the exterior of said device being at the bottom thereof, whereby combustion within said receptacle creates a draft from said grate out 125 through the perforations in said receptacle.

3. An orchard heater as described in claim 4 in which the height of said grate is limited to a point substantially below the top of the tubular member, whereby the full volume of the upper portion of said member may be utilized as a fuel magazine.

4. An orchard heater comprising a vertical tubular receptacle, a lower zone of which contains draft apertures and serves as a combustion 135 chamber, and an upper zone of which is substantially airtight to serve as a magazine for fuel, grate means for supplying air into said receptacle, whereby a draft may be created outwardly through said apertures, a damper sleeve surrounding said receptacle and movable vertically to cover and close at least a part of said apertures whereby the rate of burning may be controlled, said damper sleeve being open at both ends, and a removable cover for the top of said receptacle whereby the heater may be refueled without disturbing said damper sleeve, the upper end and top of said tubular receptacle being entirely closed whereby combustion of fuel within the upper part of said receptacle is pre- 150 vented, said sleeve serving as a means for adjustably enlarging the size of the storage receptacle as the size of the combustion chamber is reduced and vice versa.

5. An orchard heater, comprising a vertical tubular receptacle, a lower zone of which contains draft apertures a grate in the lower end of said receptacle for supplying air thereinto, and an expansible and contractable tubular sleeve surrounding said receptacle and movable vertically to variably cover the apertures in said receptacle, said sleeve when expanded being freely movable with respect to said receptacle, and when contracted forming a substantially airtight fit therewith, the upper end and top of said tubular receptacle being entirely closed whereby combustion of fuel within the upper part of said receptacle is prevented, said sleeve serving as a means for adjustably enlarging the size of the storage receptacle as the size of the combustion chamber is reduced and vice versa.

6. An orchard heater comprising a vertical tubular receptacle, a lower zone of which contains draft apertures and serves as a combustion chamber, and an upper zone of which is substantially airtight to serve as a fuel magazine, grate means for supplying air into said receptacle, whereby a draft may be created outwardly through said apertures, and a split damper sleeve surrounding said receptacle and movable vertically to cover and close at least a part of said apertures the upper end and top of said tubular receptacle being entirely closed whereby combustion of fuel within the upper part of vsaid receptacle is prevented, said sleeve serving as a means for adjustably enlarging the size of the storage receptacle as the size of the combustion chamber is reduced, and vice versa, and means for clamping said sleeve tightly about said member.

7. An orchard heater comprising a vertical tubular receptacle containing draft apertures grate means extending upwardly into said receptacle from adjacent the bottom thereof, and an expansible and contractable tubular sleeve surrounding said member and movable vertically to variably cover the apertures in said receptacle, said sleeve when expanded being freely movable with respect to said member and when contracted forming a substantially airtight closure thereabout, the upper end and top of said tubular receptacle being entirely closed whereby combustion of fuel within the upper part of said receptacle is prevented, said sleeve serving as a means for adjustably enlarging the size of the storage receptacle as the size of the combustion chamber is reduced, and vice versa.

8. An orchard heater for burning solid fuel, comprising a vertical tubular fuel container, and a base comprising a central hollow grate extending up into said container, and an oil receptacle surrounding said grate, said oil receptacle having walled draft apertures extending upward therethrough to supply air for combustion, while retaining oil in said receptacle.

9. An orchard heater for burning solid fuel, comprising a vertical fuel container, a fuel supporting base for the container, a hollow grate supported by said base and extending upwardly into the container, an opening in said base permitting the entrance of air to the interior of said grate, said grate having a base of smaller dimensions than said first named base, an oil receptacle means located below said hollow grate, whereby the flame produced from said oil passes at least in part through said grate to ignite solid fuel thereabove, and means whereby said oil receptacle may be filled with oil.

GILBERT W. NIGG. 

